Image-guided stereotactic body radiotherapy for primary kidney cancer (STONE)

Prospective Observational Trial of Image-guided Ablative STereotactic bOdy Radiation Therapy for Primary kidNey Cancer: the STONE Trial

Observational Istituto Clinico Humanitas · NCT07299357

This will try high-dose, focused radiation (SBRT) to treat adults with a single small primary kidney cancer who are not good candidates for surgery or who decline surgery.

Quick facts

Study typeObservational
Enrollment53 (estimated)
Ages18 Years and up
SexAll
SponsorIstituto Clinico Humanitas Academic / other
Drugs / interventionsradiation
Locations2 sites (Milan, Milan and 1 other locations)
Trial IDNCT07299357 on ClinicalTrials.gov

What this trial studies

This observational registry collects data from routine clinical practice on patients receiving image-guided stereotactic body radiotherapy (SBRT) delivering ablative doses in a few high-dose fractions to primary renal tumors ≤7 cm. It enrolls adults with histologically confirmed cT1 renal cell carcinoma who are medically inoperable, at high surgical risk, or have declined surgery, and excludes those with metastatic disease, prior radiotherapy to the same site, or very poor kidney function. No study-specific procedures are required beyond standard clinical care and follow-up imaging to monitor tumor response and kidney function. The compiled safety, kidney function, and local control outcomes aim to support broader adoption of SBRT as a noninvasive option for inoperable primary kidney tumors.

Who should consider this trial

Good fit: Adults (≥18) with histologically confirmed single cT1 renal cell carcinoma ≤7 cm, ECOG 0–2, medically inoperable or at high surgical risk or who have declined surgery, without metastases and with eGFR ≥30 mL/min are ideal candidates.

Not a fit: Patients with metastatic disease, tumor diameter >7 cm, prior radiotherapy to the same site, eGFR <30 mL/min, or life expectancy under three months are unlikely to benefit from this approach.

Why it matters

Potential benefit: If successful, this approach could provide a noninvasive, outpatient option to control or cure small primary kidney tumors while avoiding surgery and preserving kidney function.

How similar studies have performed: SBRT is already used successfully for many tumor types and small observational series for renal cell carcinoma report promising local control, but randomized, definitive evidence for ablative SBRT in primary kidney cancer is limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age ≥ 18 years
* ECOG performance status 0 - 2
* Histologically confirmed diagnosis of primary RCC
* cT1 stage tumor with single lesion with maximum diameter of 7 cm
* Medically inoperable or at high risk of complication from surgery, or declined surgery
* Absence of metastatic disease
* Written informed consent

Exclusion Criteria:

* Estimated glomerular filtration rate (eGFR) \< 30 mls/min
* Previous radiotherapy on the same site
* Previous systemic therapy for RCC
* Tumor diameter larger than 7 cm
* Presence of metastatic disease
* Life expectancy \< 3 months

Where this trial is running

Milan, Milan and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Renal Cancerrenal cancerstereotactic body radiotherapyradiotherapycancer treatmentrenal cancer treatmentsurgery
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.